We’ve all heard of this term quite a lot. We even know what they look like. So you might refer to your memory stick or pen drive as flash drive or you might call the memory card in your game console as a flash memory card. But exactly what is flash memory? And what are flash memory cards? To understand this, it is essential to understand that there are essentially two types of memory – Volatile and Non-volatile. Flash memory is one type of non-volatile memory. A flash memory card is a device that can store data using flash memory.
Volatile memory is that which is lost when there is no electricity powering the storage device. An example of this is the RAM. Data get stored on the RAM only when your computer is switched on and only the data that you are currently running or active will be transferred to the RAM. Once the computer is switched off all the data on the RAM are lost – therefore you have to ‘save’ everything you’ve been working on. When you save, you’re actually converting the volatile data stored on the RAM into non-volatile data that will get stored on the hard disk. The hard disk is a non-volatile memory device. Data once saved there will remain there even when the computer is switched off. If you have a portable hard disk, you can even transfer the data from one computer to another. This is the reason unsaved work is lost from the computer when there’s a power-cut. Of course, advanced versions of OS make it possible to retrieve your work.
Flash memory is a type of non-volatile memory that has become quite popular as a means to backing up, transferring and moving data from one device to another. Thus, we have flash drives (pen drives), memory sticks, SmartMedia and flash memory cards that are used widely whenever memory is required to be stored without electricity supply from a device. There are quite a few reasons as to why flash memory cards are so popular:
1. They are compact. If you look at some of the flash drives and flash memory cards, they are much smaller than your hard disk – some hardly the size of a currency coin.
2. They are also much lighter. This makes it easier to carry around than it does a portable hard disk
3. They can be accessed much faster.
4. Unlike the hard drive, it has no moving parts. The hard disk, to some extent is a mechanical device. With a flash memory card, it is completely electronic, so there are no moving parts and no noise.
The only drawback that keeps us from using a flash drive instead of a hard drive in our PCs is the cost per capacity which is quite high in the case of flash drives. However, when it comes to a back up storage medium, flash memory cards are by far the bets option.
The first flash memory card was called the floppy disk or the SmartMedia card. It was quite a simple device and contrary to current opinion, it was highly reliable and companies that initially manufactured the floppy disk gave customers a lifetime warranty. It came in storage capacities of 2 MB and 128 MB was quite compact, measuring about 45mm X 37mm X 1mm. Initially computers came with two floppy drives – A and B. Although SmartMedia are hardly manufactured today, computers still have A and B drives dedicated to floppy drives.
Although the SmartMedia cards were discontinued, newer, more compact and higher capacity flash memory cards flooded the market and continue to do so. CompactFlash is a well known flash memory card manufacturer and produces cards that are smaller, however thicker than floppy disks. They also store as much as 100 GB of data. Other than CompactFlash, many other companies produce flash memory cards in different sizes, capacities for different devices. All such cards are standardized by the PCMCIA and hence can be used in a variety of devices.